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A mathematical model which describes the quasistatic frictional contact between a piezoelectric body and a deformable foundation is studied in this paper. A nonlinear electro-viscoelastic constitutive law is used to model the piezoelectric material. The contact is described with the normal compliance condition and a version of Coulomb's law of friction. A variational formulation of the model, in the form of a coupled system for the displacements and the electric potential, is derived. The existence of a unique weak solution of the model is established under a smallness assumption of the friction coefficient. The proof is based on arguments of evolutionary variational inequalities and fixed points of operators. [ABSTRACT FROM AUTHOR]

The propagation of SH waves is studied in two bonded semi-infinite material, one piezoelectric and the other piezomagnetic. Both materials are functionally gradient materials. The material properties of the two materials vary in two directions, one parallel to the interface and the other perpendicular to the interface. The dispersion relations are obtained in explicit forms for different forms of the non-homogeneities. The effects of gradient variation about material constants on the frequency of SH waves and on the wave numbers are shown graphically. [ABSTRACT FROM AUTHOR]

This paper describes the development of screen printed vibration energy harvesters developed at the University of Southampton. The mark 1 harvester developed very low levels of power (2 μW) due to the poor piezoelectric properties of the printed film. Properties were improved by blending particle sizes and optimising firing and poling conditions. The new piezoelectric paste was applied to harvesters developed for the EU funded project TRIADE. Power outputs have improved to 240 μW from an excitation vibration of 0·29grms (g=9·8 m s-2) at 67 Hz. Multilayer structures also demonstrate further improvements, and the harvester has been demonstrated powering an autonomous wireless sensor system for condition monitoring. [ABSTRACT FROM AUTHOR]

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Information about several papers discussed at the symposium titled the Twenty-First International Symposium ((ISIF2 2009) on integrated ferroelectrics and functionalities which was held in September 27, 2009 in Colorado Springs, Colorado. Topics discussed in the symposium include ferroelectric thin films, piezoelectric, and high-k dielectric materials. The symposium further discussed phase change memories, magnetoelectric materials and biomolecular polarizable interfaces.

The new type of piezoelectric vibration accelerometer was studied, which sensitive element is cymbal piezocomposite transducer with 2-(0)-2 connectivity rather than conventional piezoelectric ceramic. The temperature property of output voltage of this new piezoelectric vibration accelerometer was investigated. Put the temperature sensor DS18B20 into the vibration accelerometer to detect the inner temperature properties of the vibration accelerometer. Using microcomputer to record the static output voltage values and gained the relationship between the temperature and static output voltage. Designed the artificial neural network module and compensated the output voltage error produced by temperature drift. The result showed that the relative error of static output voltage was decreased from 26.73% to 3.66% in the temperature range of -20°C to 60°C. The compensation method based on the artificial neural network can be used for compensating the temperature properties of output voltage sensitivity of vibration accelerometer. [ABSTRACT FROM AUTHOR]

Barrel unimorph is composed of the metal barrel shell and piezoelectric ceramic disc affixed on the shell bottom, its flexural vibration is investigated with modeling and experiment. The barrel unimorph was modeled with finite-element method to analyze the vibration mode and calculate the relationship between the structure dimension and vibration frequency. The factors influencing resonance frequency were also discussed. According to the simulation, the structure of the barrel unimorph was optimized and the samples were fabricated in practice. The vibration mode of the sample was measured. The results show that the frist step resonance vibration frequency of the sample agrees well with the calculation by finite-element method. [ABSTRACT FROM AUTHOR]

A strong dependency of the processing route on the tetragonality conditions and surface texture of high energy ball milled commercial powders and ceramics of BaTiO3 sintered at different temperatures is reported in the current paper. Tetragonality and surface texture were analysed in both powders milled at different times and ceramics sintered at different temperatures by X-ray diffraction using a method for the deconvolution of the (002)t y (200)t diffraction peaks that appear in 44≤2θ≤46°. Tetragonality of milled powders continuously reduced as a function of milling time. The intensity ratio Iint(002)/Iint(200) was related to the textured surface. The texture effect was always observed in samples sintered below 1613 K. The 'untextured' condition was only demonstrated in the sample sintered at 1673 K. These results can be explained with residual stresses in the crystalline structure of sintered bodies. Finally, characterisation with piezoelectric response micrographs allowed the observation of abnormal domain arrays in a {011} oriented barium titanate crystallite, which were correlated with the texturisation phenomena measured in the sintered bodies. [ABSTRACT FROM AUTHOR]

A strong dependency of the processing route on the tetragonality conditions and surface texture of high energy ball milled commercial powders and ceramics of BaTiO3 sintered at different temperatures is reported in the current paper. Tetragonality and surface texture were analysed in both powders milled at different times and ceramics sintered at different temperatures by X-ray diffraction using a method for the deconvolution of the (002)t y (200)t diffraction peaks that appear in 44≤2θ≤46°. Tetragonality of milled powders continuously reduced as a function of milling time. The intensity ratio Iint(002)/Iint(200) was related to the textured surface. The texture effect was always observed in samples sintered below 1613 K. The 'untextured' condition was only demonstrated in the sample sintered at 1673 K. These results can be explained with residual stresses in the crystalline structure of sintered bodies. Finally, characterisation with piezoelectric response micrographs allowed the observation of abnormal domain arrays in a {011} oriented barium titanate crystallite, which were correlated with the texturisation phenomena measured in the sintered bodies. [ABSTRACT FROM AUTHOR]

A bibliography is given containing 2121 references published during 2006 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles with complete bibliographic citations. References to patents and doctoral dissertations will be published in Guide 30. This bibliography is the continuation of a series published semi-annually. [ABSTRACT FROM AUTHOR]

A bibliography is given containing 1683 references published during 2005 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles, patents and dissertations with complete bibliographic citations. References in which the first author's name begins with letters between N and Z are given in the current guide. Journal articles and patents by authors with names beginning with the letters A through M were published in Guide 27. This bibliography is the continuation of a series published semi-annually. [ABSTRACT FROM AUTHOR]

This paper is devoted to the analysis of effective electromechanical properties and their maxima in 0-3-type composites based on (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 single crystals. It is shown that the electromechanical interaction between the single-crystal and polymer components with the anisotropy of their piezoelectric coefficients e33(n)/|e31(n)| ≥ 5 results in relations d33* ≈ e33*s33*E, g33* ≈ h33*s33*D, and kt* ≈ k33* for the electromechanical constants. These relations hold in a wide range of volume fraction and aspect ratio of the spheroidal inclusions in the 0-3 composite. An increase in the maximum values of different effective parameters is expected by forming a system of oblate air pores in the matrix. [ABSTRACT FROM AUTHOR]

A formulation of the hybrid Laplace transform-finite element method is presented to deal with a thermoelastic-piezoelectric coupled two-dimensional thermal shock problem of a thick, infinite piezoelectric plate. The results are applicable to the generalized thermoelasticity theories: Lord-Shulman, Green-Lindsay, and Chandrasekharaiah-Tzou theories, as well as the classical coupled theory. By means of the Laplace transform and numerical Laplace inversion the problem is solved. The results are given and illustrated graphically. From the distributions, the wave type heat propagation in the piezoelectric plate can be found. A comparison with results given in literature proves the good performance of the used method. [ABSTRACT FROM AUTHOR]

In this paper, the directivity is optimized for a PZT based microspeaker array. The SiO2/Pt/Pb(Zr,Ti)O3/Pt/Ti/SiO2 multimorph structure has been designed and fabricated to be the microspeaker cell using silicon based micro-machining process. The membrane size of the single transducer cell is 1000× 1000× 2.5 μ m3, and the main resonance frequency is located near 68 kHz (λ = 5 mm). Directivity is a very important parameter for microspeaker array. Dissimilar arrangement of the cells in transducer array could cause different directivity performance. After comparison, when achieving a good transmitting directivity, the square combined plane array has the smallest area. [ABSTRACT FROM AUTHOR]

The paper presents exact solutions for thick composite beams composed of multiple lamina made of arbitrary orthotropic elastic and/or piezoelectric materials. A state-space formulation is presented through the formulation of a transfer matrix relation from layer to layer and therefore a global relation governing the top layer through the bottom layer can be derived. No shear correction factor needs to be considered because the thick beam is assumed as a plane-stress problem in the cross section. Some exemplary examples with exact modeling and numerical solutions are presented to illustrate the application of the method. The effects of combination of mechanical and electrical loadings are also presented. Especially, the higher-mode deflection appearance instead of simple fundamental mode of the beam under uniform loads is discussed. [ABSTRACT FROM AUTHOR]

This paper addresses the actuator effect of a piezoelectric anisotropic plate model, depending on the location of the applied electric potentials, and for different clamped boundary conditions. It corresponds to integer optimization problems, whose objective functions involve the displacement of the plate. We adopt the two-dimensional piezoelectric anisotropic nonhomogeneous plate model derived in Figueiredo and Leal [1]. This model is first discretized by the finite element method. Then, we describe the associated integer optimization problems, which aim to find the maximum mechanical displacement of the plate, as a function of the location of the applied electric potentials. In this sense, we also introduce a related multi-objective optimization problem, which is solved with genetic algorithms. Several numerical examples are reported. For all the tests, the stiffness matrices and force vectors have been evaluated with the subroutines planre and platre , of the CALFEM toolbox of MATLAB [2], and the genetic algorithms have been implemented in C ++ . [ABSTRACT FROM AUTHOR]

In this paper, disk-type ultrasonic motor using a combination of radial and bending vibration modes is newly designed and fabricated. The characteristics of the test motor are also measured. By means of traveling elastic wave induced at the surface of circumference of the elastic disk, a steel bar in contact with the surface of circumference of elastic disk bonded onto the piezoelectric ceramic disks is driven in both directions by changing the sine and cosine voltage inputs. The stator of the motor is composed of two sheets of piezoelectric ceramic disk to bond onto both surfaces of a elastic disk, respectively. As the results, the diameter of elastic body is increased, the resonant frequency is decreased. The resonant frequency of the stator is about 92 kHz, which is composed with piezoelectric ceramic disks of 28 mm in diameter and 2 mm in thickness, and an elastic body of 32 mm in diameter and 2 mm in thickness. A driving voltage of 20 Vpp produces 200 rpm with a torque of 1 Nm and an efficiency of about 10%. [ABSTRACT FROM AUTHOR]

This paper describes the electrical properties of the CSD-derived ferroelectric PZT thin films on the oxide electrode of LaNiO 3 (LNO), which can improve the electrical fatigue for the PZT thin film. We successfully control the orientation of the resulting LNO thin film electrode by the molecular design of the precursor solution to control the orientation of the PZT thin film with a MPB composition on the LNO. As a result, PZT/LNO thin film capacitors exhibited superior electrical properties with no fatigue, not only for remanent polarization but also for piezoelectric and dielectric properties. [ABSTRACT FROM AUTHOR]

Piezoelectric aging behavior of 0.2(PbMg 1/3 Nb 2/3 O 3 )-0.8(PbZr 0.475 Ti 0.525 O 3 ) multilayer ceramic actuators have been investigated by applying unipolar wave function at the room temperature. 5×5×5 mm 3 size multilayer ceramic actuators were fabricated by tape casting methods. Effective electromechanical coupling coefficient k eff and pseudo-peizoelectric constant d 33 were calculated and discussed. Different unipolar electric fields were applied to the actuators to investigate aging behavior in the multilayer ceramic actuators. The aging dependencies of cycle and electric field were simulated and fitted to the linear logarithmic stretched exponential law. Finally true-psuedo-piezoelectric constant was extracted and modeled from the linear logarithmic stretched exponential law. [ABSTRACT FROM AUTHOR]

The actuation behavior of multilayer ceramic actuators (MCA) using PMN-PZT ceramics was investigated under the combined high electromechanical loading. When electric field and compressive stress are simultaneously applied to the ceramics, the piezoceramics is expected to be different from that of ceramics induced by only one quantity, electric field or mechanical load. This property difference was estimated via piezoelectric equation. [ABSTRACT FROM AUTHOR]

A bibliography is given containing 1887 references published during 2004 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles and patents with complete bibliographic citations. Journal and patent references from 2004 in which the first author's name began with letters between A and K were given in Guide 25 (published previously). Journal articles and patents by authors with names beginning with the letters L through Z are published in the present Guide. This bibliography is the continuation of a series published semi-annually. [ABSTRACT FROM AUTHOR]

This paper reports the first evidence of piezoelectric properties of K4LiH3(SO4) 4 KLHS crystal in the temperature range 12 K-300 K. Moreover, the anomaly in the elastic properties of this crystal observed at about 50 K by the composite oscillator bar method has been related to a proton glassy state. The elastic properties of the crystal determined by piezoelectric measurements revealed an anisotropy and dispersion in the (110) plane. [ABSTRACT FROM AUTHOR]

This paper reports on a 2.3 mm × 2.3 mm polymer micro-electromechanical systems (MEMS) for air transducer applications. The MEMS, used as a receiver of ultrasonic signal, has a suspended membrane structure. A 2.7 μ m thick poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] 70/30 mol% copolymer was spun on a silicon dioxide/silicon substrate and then poled in-situ. The Si substrate was then etched from the backside by anisotropic chemical etching in KOH to produce a P(VDF-TrFE)/SiO 2 /Si suspended membrane structure. The displacement of the membrane was measured by means of a laser vibrometer. The maximum deflection at the center of the membrane was 0.9 μ m at 40.8 kHz under an input drive of 7 V. A commercial air transducer was used as the transmitter to emit ultrasound at 40.8 kHz. The MEMS acoustic transducer, which has similar resonance frequency, was used as the receiver. The temporal response of the MEMS and its sensitivity were measured. The result suggested that the MEMS has potential for monitoring ultrasound emission. [ABSTRACT FROM AUTHOR]

This paper deals with the characterization of multi-layer actuators and bulk PZT ceramics under the influence of an applied electric field. The displacement profile of materials and devices with evaporated reflective dielectric layers was measured using a double-beam laser interferometer at room temperature. The displacements of 3 mm thick plates of bulk soft PZT were characterized to determine bulk material properties. The tested multi-layer actuator devices consisted of 20 layers, with each layer being 87 micrometers thick. The results of “point to point scanning” of displacement across piezoelectric materials are presented and the effective actuation area of the actuator displacement is determined. Comparisons are made of the behaviour of the bulk ceramics and the actuator. In addition to experimental measurement, representative coupled-field finite element model was constructed to compare with experimental x - y displacement data of multi-layer actuator. [ABSTRACT FROM AUTHOR]

Comments on a symposium on ferroelectricity and piezoelectricity that part of the 13th International Materials Research Congress in Mexico in August 2004. Range of issues and subject matter discussed during the symposium; Keynote speakers; Implications on studies of integrated ferroelectrics.

A comparative study of Love-type wave vibrations in a distinct piezoelectric (PE) material thin film with a highly and weakly dielectric interface with an elastic pre-stressed elastic plate is investigated analytically. Using the PZT-2, PZT-4, PZT-5H, LiNbO3 and BaTiO3 numerical data for the PE material, we achieved significant outcomes of PE and flexoelectric effect in the study. Dispersion equations are achieved analytically for both electrically open and short cases together with highly and weekly conducting interfaces in the transcendental complex form. Outcomes specify that microstructures having flexoelectricity has a significant influence on dispersion features. The existence of flexoelectricity shows that complex phase velocity with a positive imaginary part increases the phase velocity of considered waves with time. Numerical results are highlighted graphically and validated with existing results. The present study is a prior attempt to show the flexoelectricity influence with weekly and highly conducting interfaces and also to show that the outcomes are significant to obtain better surface acoustic wave device's performance. [ABSTRACT FROM AUTHOR]

A bibliography is given containing 2039 references published during 1999 and 2000 on piezoelectric and pyroelectric properties of materials and their applications. It includes journal articles, patents and doctoral dissertations with complete bibliographic citations. This bibliography is the continuation of a series published semi-annually. [ABSTRACT FROM AUTHOR]

Human living skin generates an increase in the skin potential when compressed. This was measured on eight subjects with a matrix of nine Ag/AgCl electrodes. The potential increased with the pressure until it reached a maximum. When the pressure was increased stepwise, the response showed an overshoot at each step. Human cadaver skin did not show these potential increments. Neither did pads of collagen, paper tissue soaked in a KCl solution, nor layers of cultured keratinocytes. Three theories are described that may explain the origin of the measured skin potentials. The first is based on the piezoelectric characteristics of proteins in the skin. The second theory assumes that the skin is a charged membrane which generates a streaming potential when deformed. A third theory is proposed in which deformation of absorbed charged protein layers on structures in the skin change the alignment of Donnan potentials in the surrounding tissue. [ABSTRACT FROM AUTHOR]

The paper deals with the piezoelectric coefficients measurements of PZT type piezoelectric ceramics in a wide temperature range. The single beam micro-interferometer, working inside of helium optical cryostat in the range 150-330 K was used. The original design of optical cryostat was realized for the suppression of cooling system vibrations. The piezoelectric coefficients d 33 and d 31 were obtained by laser interferometer measurements of the sample strain, induced by an applied electric field. The temperature dependences of both d 33 and d 31 were fitted by polynomial function and hydrostatic piezoelectric coefficients d h were estimated from these fitted values. The temperature dependence of the piezoelectric coefficients can be used to study extrinsic and intrinsic contributions and their temperature behaviour. For this reason it is desirable to shift the low temperature limit down to 20 K and to increase the accuracy of the piezoelectric coefficients d 33 and d 31 measurement. [ABSTRACT FROM AUTHOR]

Interrelations of domain wall (extrinsic) contributions to dielectric, piezoelectric and mechanical properties of ferroic samples are a hot subject of both theoretical and experimental research. Recently, we have derived theoretical formulas for such contributions, using model of composite layer sample: central single-crystal ferroelectric-ferroelastic layer, isolated from electrodes by passive layers. Here we present more general results, discussing the dependence of the contributions on geometric and material parameters of the composite and including in a special case intrinsic piezoelectricity. We also discuss the above-mentioned interrelation and compare our results with measurements of all the contributions on the same RDP sample in a wide temperature interval under the phase transition. It seems that both calculated and observed results remind of the so called Pippard-Janovec thermodynamic relations. [ABSTRACT FROM AUTHOR]

A bibliography is given containing 1817 references published during 1999 on piezoelectric and pyroelectric properties of materials and their applications. It includes journal articles and some conference proceedings. Complete bibliographic citations and additional information such as language and original sources of translations are given. This bibliography is the continuation of a series published semi-annually. [ABSTRACT FROM AUTHOR]

In order to optimize the broadband response of a piezoelectric transducer, different impedance matching procedures are used, looking for a compromise between efficiency and bandwidth. In this paper a general methodology for the evaluation of acoustic and electrical matching schemes is presented. Broadband acoustic impedance matching schemes are evaluated in the frequency domain using the transmission line analogy. Electrical matching networks at the reception stage are evaluated using the transmission matrix approach. In practical cases of ultrasonic imaging and NDE, electronic "spike" generators based on capacitive discharges are used. The special topology of such generators (including semiconductor devices) conditions the electrical driving pulse at the transducer terminals. This driving waveform (determined by the interactions among the spike generator, the electrical matching network and the transducer) is approximately evaluated in the frequency domain for the low Megahertz range. Several examples in emission and reception illustrate the methodology, including a comparative study of criteria proposed for the optimum design of quarter-wave transmission line matching layers. [ABSTRACT FROM AUTHOR]

Multi-layer actuators are used for applications that require large displacements at comparatively low drive voltages compared to monolithic materials. The aim of this paper is to demonstrate methods by which the complete device is characterised by measuring (i) the displacement profile using a non-contact three-dimensional profilometer and (ii) an adapted piezometer to measure the charge per unit force of the device. Experimental measurements are compared with predicted values using a simple analytical analysis. [ABSTRACT FROM AUTHOR]

Commercial ultrasonic equipment employing wideband piezoelectric transduction systems, usually operate in through-transmission (T-T) or pulseecho mode. These systems, which include one or more piezoelectric stages, are widely used in areas such as biomedical imaging, non-destructive evaluation and characterization of material properties. In this paper different electrical T-T and pulse-echo simulation schemes, modeling piezoelectric devices and associated pulsed electronics, are proposed and used for studying temporal responses under practical conditions. Employing PSPICE, several responses are analyzed for specific devices in the MHz range. Two alternative electrical models for the reception stage are comparatively evaluated in pulseecho situations. Comparisons between simulated performances and experimental measurements are also presented, showing a good agreement in T-T and pulse-echo signal conditions. [ABSTRACT FROM AUTHOR]

In this paper, nanoscale ferroelectric and piezoelectric properties (e.g. cartography of the piezoelectric coefficient after poling and polarisation direction) of sol-gel PZT thin films are studied using a modified Atomic Force Microscope (AFM). Polarisation patterns are created, and then imaged after more than one year. Hysteresis loops are recorded and it is shown that their shape and related parameters (remanent polarisation and coercitive field) are strongly dependant on the experimental conditions. [ABSTRACT FROM AUTHOR]

The experimental and simulation of dielectric, AC resistivity and dielectric resonance and anti-resonance data on (Na0.5Bi0.5)(NdxTi1-2xNbx)O3] ceramics were carried out using modified Lorentz equations as proposed by us instead of well know and generally applied laws like Arrhenius law and formulas on piezoelectricity to obtain activation energy, relaxation time, piezoelectric charge constant and voltage constant directly from the experimental data. The piezoelectric charge constant (d33) evaluated from the modeling are 864.64 p.m/V and 122.40 p.m/V; whereas the piezoelectric voltage constant (g33) are 10.88 p.m2/C and 8.55 p.m2/C for x = 0.0125 and 0.025 ceramic samples, respectively. [ABSTRACT FROM AUTHOR]

In 1968-69 Bleustein and Gulyaev discovered a new type of piezoelectric surface waves, for any material in class C 6 ν (6 m m) , having no counterpart in a purely elastic homogeneous material of the same elastic symmetry as the piezoelectric material. This discovery generated an extensive literature on the subject, with extensions to piezoelectromagnetism too. Here we study generalizations of this type of surface waves in the presence of thermal fields for thermo-piezoelectric materials with hexagonal symmetry. The exact solutions are written for a class of stationary waves varying harmonically with time, which couple both modes of propagation. [ABSTRACT FROM AUTHOR]

The article introduces a series of papers on phase transition materials and piezoelectricity. In particular, these papers discuss materials having unusually strong piezoelectric character and contain experimental results on x-ray and neutron diffraction, dielectric and infrared spectroscopy, the existence of morphotropic phase boundaries, and the relaxor/ferroelectric crossover in disordered materials.

Flexoelectricity is a symmetry independent electromechanical coupling phenomenon that outperforms piezoelectricity at micro and nanoscales due to its size-dependent behavior arising from gradient terms in its constitutive relations. However, due to this gradient term flexoelectricity, to exhibit itself, requires specially designed geometry or material composition of the dielectric material. First of its kind, the present study put forward a novel strategy of achieving electric field gradient and thereby converse flexoelectricity, independent of geometry and material composition of the material. The spatial variation of the electric field is established inside the dielectric material, Ba0.67Sr0.33TiO3 (BST), by manipulating electrical boundary conditions. Three unique patterns of electrode placement are suggested to achieve this spatial variation. This varying direction of electric field gives rise to electric field gradient, the prerequisite of converse flexoelectricity. A multi-physics coupling based theoretical framework is established to solve the flexoelectric actuation by employing isogeometric analysis (IGA). Electromechanically coupled equations of flexoelectricity are solved to obtain the electric field distribution and the resulting displacements thereby. The maximum displacements of 0.2 nm and 2.36 nm are obtained with patterns I and II, respectively, while pattern III can yield up to 85 nm of maximum displacement. [ABSTRACT FROM AUTHOR]

Energy harvesting is a conducive approach that assists to create sustainable and eco-friendly environment. A piezoelectric tile is capable of harvesting vibrational energy from footsteps. A lumped parameter model is introduced for the piezoelectric energy harvesting tile (PEHT) by using PZT-PZNM ceramic with stainless steel (SUS-304) substrate. A study on the dependency of tip mass, capacitance, load resistance, frequency, and electrically induced damping coefficient on voltage and generated power is conducted to analyze the behavior of the PEHT. The effect of materials on piezoelectric performance is also studied by the use of different ferroelectric relaxors and ceramics including 0.955Pb(Zn1/3Nb2/3)03–0.045PbTi03 (PZN-0.045 PT), 0.70Pb(Mg1/3Nb2/3)O3–0.30PbTiO3(PMN-0.3 PT), piezoelectric ceramics from Rostov-on-Don (Russia) (PCR-7) and Pb[ZrxTi1–x] O3 (PZT-5). An increment of 754% and 317% was observed in PZN-0.045 PT and PMN-0.3 PT in power while voltage increased by 192% and 104% respectively as compared to PZT-PZNM material. [ABSTRACT FROM AUTHOR]

The Internet of things (IoT) is gaining popularity due to diverse applications and market potential. They are pushed more into remote locations and developers look for a perpetual power source. The vibration energy harvester (EH) is capable to mitigate powering issues. Zinc oxide (ZnO), Polydimethylsiloxane (PDMS) and Silver (Ag) were used. However, it is observed that film grains size has a great impact i.e. large-grained films are superior to small-grained films. This work analyses impacting parameters and relevant empirical study. Scanning-Electron-Microscope (SEM), X-ray Diffraction (XRD), Electrical characterization were carried out for in-depth analysis. It is observed that 46.92 µWpeak/15.03 µWrms power is achieved in this work. [ABSTRACT FROM AUTHOR]

Piezoelectric probes in medical and industrial applications use to have a multilayer structure in order to produce short duration ultrasonic pulses. This duration is also dependent on electrical excitation. The associated electronics presents some non-linear behaviours which are not considered in conventional simulation approaches. In this paper a PSpice global model, including piezoelectric aspects and non-linear high-voltage electronics, is presented and applied to analyse a piezoelectric process in transient regime. Parameter setting in excitation energy for the driving and transient piezoelectric response is analysed, by computer simulation and parametric analysis. [ABSTRACT FROM AUTHOR]

Mechanical responses to electric stimulation in a liquid crystalline elastomer composed of cholesterol-derived mesogens were investigated. An electric-field-induced polar deformation resembling the motion of the flukes of a dolphin was observed in the temperature region of the pseudo-isotropic state of the elastomer prepared by cross-linking reaction under splay distortion. The emergence of polarisation was also confirmed above the SmA* to the pseudo-isotropic phase transition temperature, whereas no polarisation emerged in the SmA* phase. We tentatively conclude that the flexoelectric effect within splay distortion fixed by cross-linking caused the emergence of polarisation and the polar deformation. [ABSTRACT FROM AUTHOR]

Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT-xBCT) is a promising lead-free ferroelectric system with high piezoelectricity. Here we carry out phenomenological calculations to explore phase stability and electric field induced phase transition. Study of free energy variation near phase boundaries revealed ultralow energy barrier in single orthorhombic phase region and phase coexistence around inter-ferroelectric transitions. The calculated critical electric field for tetragonal-orthorhombic transition is in reasonable agreement with experimental data. Temperature–composition phase diagram under [001], [011] and [111] oriented electric field are computed, and polarization rotation associated monoclinic structures are studied. [ABSTRACT FROM AUTHOR]

The object of the study was samples of commercial piezoelectric ceramics Pb0.95Sr0.05(Zr0.53Ti0.47)O3+1% Nb2O5 (PZT-19). A series of experimental studies of the kinetics of changes in the optical transmittance of the PZT-19 ceramic samples was carried out during exposure to the full spectrum of a PESL-SF2 11 W/865 E14 fluorescent lamp. The kinetics of restoring the initial optical transmittance of samples stored in the darkness after the light exposure was studied as well. The effect of thermal annealing of samples on the erasure of a photochromic-induced color change induced by irradiation revealed. [ABSTRACT FROM AUTHOR]

In this work, an experimental model and a simplified analytical model of U-shaped atomic force microscopy (AFM) probe are described. The effects of surface elasticity, surface piezoelectricity and thermal loading on U-shaped probe are considered for the first time. The obtained experimental results are for commercial U-shaped probe AN2-300 when it is mounted on the afm+ system. The results indicate that modeled beams on the basis of the couple stress theory have higher stiffness than the modeled ones based on the classical continuum theory. It is shown that both the surface elasticity and surface residual stress influence the natural frequencies. Also, it can be observed that the piezoelectric field shows both decreasing and increasing effects depending on the sign of the voltage. In order to check the accuracy of the presented theory for the U-shaped AFM probe, the analytical results achieved by the modified couple stress theory are compared with experimental results, and it is found that they are in a very good agreement. This work will improve understanding the vibrational behavior of U-shaped probes and may be of special interest in design and application of nanoscale structures. [ABSTRACT FROM AUTHOR]

(100 − x)PVDF–(x) PZT (PVDF: Polyvinylidene Difluoride and PZT: Lead Zirconate Titanate) composite was prepared in 0–3 connectivity by the solvent casting methods. The piezoelectric co-efficient is found to be increased with the increase in PZT concentration in the PVDF matrix. It is due to the increase of β phase of PVDF as well as lattice strain in PZT. The incorporation of PZT ceramics in the PVDF matrix causes an increase in storage loss modulus of the sample. The tanδ decreases due to incorporation of PZT ceramics in the PVDF matrix. The piezoelectric and mechanical properties are found to be increased in the PVDF-PZT composite compare to that of PVDF. [ABSTRACT FROM AUTHOR]

In this study, longitudinal stress waves of viscoelastic rods bonded with piezoelectric layer are tackled comparatively. The analysis is based on one-dimensional wave theory and various rheological models are considered. The new viscoelastic wave equations that include the effect of piezoelectric material layer are developed. The numerical illustrations of the wave characteristics are presented in detail. Especially, the attenuation illustrations can be regarded as significant novelties of this study for the present literature. This study can be helpful in modelling laminated piezoelectric structures having viscoelastic core as suitable to desired operating conditions. [ABSTRACT FROM AUTHOR]

A unit cell-based micromechanical model is presented to investigate the effect of PZT-7A piezoelectric interphase on the effective magneto-electro-elastic properties of CoFe2O4 piezomagnetic matrix composites reinforced with piezoelectric fibers. The carbon fiber is coated with the PZT-7A piezoelectric material. The model is used to determine effective stresses, electric and magnetic field properties of the smart composite. By applying loads over the RVE of unit cell model in electric and magnetic fields, the in-plane strains, corresponding piezoelectric constants and corresponding piezomagnetic constants are obtained. The influences of interphase thickness on effective magneto-electro-elastic properties are investigated at different piezoelectric fiber volume fractions. [ABSTRACT FROM AUTHOR]

The in-situ observation of pressure inside a sample chamber was made by exploiting the piezoelectric effect in manganin wire. This was done by considering temperatures of room temperature (±1°C), 600°C (±3°C), and 900°C (±3°C), pressure range of 0–2.4 GPa (±0.1 GPa), and the inferring a relationship between the relative resistance of manganin wire and the pressure inside the sample chamber for the different temperatures, allowing the pressure to be found. [ABSTRACT FROM AUTHOR]